Vacuum cleaner



G. E. LOFGREN VACUUM CLEANER April 20, 1937.

Filed March 15, 1935 2 Sheets-Sheet 1 7?4 46;, ATTORNEY.

G. E. LOFGREN VACUUM CLEANER A ril 20, 1937.

Filed March 15, 1955 2 Sheets-Sheet 2 I nyvggToR, 7 W

@/M 5 ATTORNEY.

Patented Apr. 20, 1937 VACUUM CLEANER Gustaf Elna: Lofgren, Riverside,Conn., asslgnor to Electrolux Corporation, Dover, Del., a corporation ofDelaware Application March 13, 1935, Serial No. 10,759

14 Claims.

My invention relates to vacuum cleaners, and more particularly to vacuumcleaners oi the type wherein the dust separating member is containedwithin a casing.

One of the objects of my invention is to provide a vacuum cleaner ofthis type which is provided with a removable receptacle, such as adrawer, for receiving the dust separated from the air stream by the dustseparating member. A

receptacle of this kind may be more readily removed and emptied than cana dust bag.

A further object oi my invention is to provide means for mechanicallydlslodging dust adhering to the dust separating member, thus causing thedust to be collected in the receptacle. In the embodiment illustrated,this removal of dust is accomplished by shaking the dust separatingmember.

A still further object of my invention is to provide an improved type01' indicating means for informing the operator when it is desirable todislodge dust adhering to the dust separating member.

Another object of my invention is to provide a dust separating memberhaving a maximum surface area.

Further objects and advantages of my invention will be apparent from thefollowing description considered in connection with the accompanyingdrawings, which form a part of this specificatlon and on which:

Fig. 1 is a cross-sectional view of one embodiment of my invention;

Fig. 2 is a front end view of the device shown in Fig. 1;

Fig. 3 is a cross-sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a perspective view of a dust collecting receptacle or drawer;

Fig. 5 is a cross-sectional view on an enlarged scale showing a detailof construction;

Fig. 61s a, cross-sectional view on an enlarged scale showing the dustindicator;

Fig. 7 is a cross-sectional view showing a different embodiment of dustseparating member;

and

Fig. 8 is a cross-sectional view taken on the line 88 of Fig. 7.

Referring more particularly to Fig. 1, reference character It)designates a casing made of rigid impervious material, such as sheetmetal. Casing l0 preferably comprises an upper stamping I l and a lowerstamping l2. These stamplngs are joined along a horizontal line, as isshown at IS. The details of this Joint are shown more particularly inFig. 5. The edge of upper stamping II is formed with an ofl-set portionH, which is bent back upon itself at IS. A strip ..of rubber or otherresilient material l6 has a hook-shaped portion I! which extends betweenthe upper edge of lower stamping I2 and offset portion Screws l8 extendthrough holes formed in lower stamping l2 and engage threaded aperturesformed in the ofi-set portion It. This portion is turned back uponitself in order to provide a greater thickness of material for screws l8to engage. The heads of screws l8 are concealed under the roundedportion I9 of strip l6. Portion l9 also serves as a bumper so that ifthe cleaner is accidentally brought into contact with a piece offurniture or the like, the furniture will not be marred.

A motor supporting member 20 is secured within one end of easing l0.Member 20 is formed with a channel portion 2| which rests within asealing ring 22 of rubber or other suitable material. Screws 23 extendthrough casing 10 and ring 22 and engage threaded apertures formed inchannel portion 2|, thus retaining member 20 securely in place. Sealingring 22 prevents the passage of air between member 20 and the casing 10.A plurality of lugs 24 are secured to channel portion 2| by bolts 24aand are distributed equidistantly around the circumference thereof.Preferably, three lugs spaced apart are provided.

Reference character 25 designates an electric motor which is providedwith lugs 26 spaced 120 apart around the circumference of the motor.Secured in these lugs are pins 21 encircled by springs 28. These pinsand springs extend through apertures formed in lugs 24, thus providing aresilient support for the motor. Spacing members 29 may be placedbetween lugs 24 and 26.

One or more fan rotors 30 are mounted on the shaft 3| of motor 25. Inthe embodiment illustrated two rotors 30 are provided. The forward rotoris surrounded by a fan housing 32 having a cylindrical portion 83. Theother rotor is surrounded by a fan housing 34 having a cylindricalportion 35. Cylindrical portions 33 and 35 are telescoped and the rearedge of each is provided with an outwardly extending flange 86. Thehousing of motor 25 is provided with a radial flange 31 against whichthe flanges 36 are clamped by means of clamping ring 38.- Ring 38 issecured to flange 31 by bolts 39. Rings of packing material 40 areprovided in order to eflect an air-tight seal between the fan housingsand flange 31. Member 28 is formed with a cylindrical portion 4| whichis eccentric with respect to channel portion 2|. A sealing ring 42 isprovided around the outer circumference of ring 38 and bears againstcylindrical portion 4! in order to effect an air-tight sealtherebetween. The left hand end of cylindrical portion 4|, as viewed inFig. 1, serves to support a member 43 having a curved surface andpreferably made of wire screen or other stiff, air-pervious material.

A dust separating member 44. preferably made of cloth having a weavesuch that it will permit the passage therethrough of air, whilepreventing the passage of dust, is supported over member 43. Dustseparating member 44 is secured at 45 to a movable tube 46. Tube 46 isrotatably and slidably mounted in a bushing 4! secured in member 43 andin a bushing 48 supported by a spider 49 supported within member 43. Acollar 'end of tube 46 is formed a handle 53, which may be grasped topull the tube out against the force of spring 5| and to rotate the tube.Dust separating member 44 is somewhat larger than supporting member 43,so that it can be pulled away from member 43 when the tube is pulledout. If the tube is pulled out suddenly, it snaps the dust separatingmember into stretched condition, thus dislodging dirt from the outersurface thereof. Rotating the tube also agitates member 44 and aids indislodging dirt. When handle 53 is released, spring 5| snaps the tubeback to its normal position.

The left hand end, as viewed in Fig. l, of lower stamping I2 is formedwith a rectangular opening 54. A drawer 55 is adapted to be inserted andremoved through opening 54. The outer end of drawer 55 is formed with aflange 56 of greater dimensions than opening 54 in order to overlap theopening and bears against the front wall of stamping l2. A sealing strip51 of rubber or other suitable material is secured to the flange 56 inorder to seal the joint between the drawer and the casing. An arm 58 issecured to stamping I2 above the center of opening 54 and extendsdownwardly so as to be within the drawer 55 when the latter is in place.Ann 58 is formed with a threaded aperture 59. A pin 68 is journalled ina bushing 6| secured in the front wall of drawer 55 and is provided atits outer end with a knurled knob 62 and at its inner end is formed withscrew threads 63 which engage threaded aperture 59. Pin 68 thus providesmeans for fastening the drawer in place and placing sealing ring 51under compression so as to effect a tight seal.

The rear wall 64 of drawer 55 is cut away, as is clearly shown at 65 inFig. 4, so as to accommodate the lower portion of supporting member 43and dust separating member 44. This cutaway portion also makes itpossible to withdraw the drawer without interference from arm 58.Inasmuch as drawer 55 is not as wide as lower stamping l2, spacingmembers 66 are secured within stamping [2 in order to center the drawerand prevent sidewise movement thereof. Deflecting members 61 are securedwithin upper stamping I l and serve to direct the dust into the drawerand prevent to a great extent accumulation of the dust in the spacebetween the side walls of lower stamping I 2 and the outside of thedrawer.

Upper stamping l l is provided with a threaded bushing 68 forming aninlet opening and adapted to receive the threaded end 69 of a hose 18.The other end of hose i8 is adapted to be connected to a suction nozzleor other air cleaning tool. A threaded bushing II is secured within anopening formed in lower stamping l 2 and serves as an outlet for air.Louvers 12 may be provided across the opening in bushing H in order todirect the air upwardly and away from the surface on which the vacuumcleaner is resting. If it is desired to use the device for blowingpurposes, hose 18 may be screwed into bushing 1|. As shown in Fig. 1,the convex surface of dust separating member 44 faces the inlet openingwith respect to the direction of air flow.

A dust indicating device is incorporated within the handle 53. The innerend of tube 46 opens within the space between dust separating member 44and the fan rotors 38. The outer end of tube 46 communicates through apassage 13 with a space 14 formed within a member 15 forming part of thehandle 53. A tube 16 surrounds the outer end of tube 46 and extendsthrough bushing 52. Tube I6 is provided with apertures 11 whichcommunicate with the space in the casing betweenthe inlet and the dustseparating member. The outer end of tube 161s threaded into member 15 at18. A passageway 19 establishes communication between tube 16 and aspace 38 formed between member 15 and a cap 8!. Member 15 and cap 81 arefastened together by means of bolts 82. A cup-shaped member 83 is formedwith an outwardly extending flange 84 which is clamped between member 15and cap 8|. The peripheral portion of the bottom 83a of member 83 servesto clamp the outer circumference of a flexible diaphragm 85 betweenmember 83 and a shoulder 86 formed in member 15. A disc 81 withdownturned edges is secured to the center of diaphragm 85 and retainsone end of a spring 88, the other end of which bears against member 15.A flat disc 89 is secured to the other side of diaphragm 85 and bearsagainst the bottom 83a of cup-shaped member 83. One or more apertures83b are formed in bottom 83a to assure that the pressure communicatedthrough passageway 19 will act on diaphragm 85. Discs 8'! and 89 aresecured to diaphragm 85 by a round headed rivet 91 or the like whichextends through the central opening in the bottom 83a.

An indicating. member 98 is pivoted at 9|,to ears 92 formed on member83. A spring 93 has one end secured to indicating member 98 at 94 andthe other end to a hook 95 formed on member 83. Spring 93 is maintainedunder tension and tends to rotate indicator member 98 in clockwisedirection as viewed in Fig. 5. A flat-bot tomed portion 96 of member 98bears against the rounded head of rivet 91 carried by diaphragm 85 andprevents the rotation of member 98. Indicator member 98 is formed with acylindrical portion 98 which is adapted to be rotated in front of anair-tight window 99. Cylindrical portion 98 bears markings so that itsposition may be determined by viewing it through window 99. Thesemarkings may consist in coloring white a part which is visible in theposition shown in Fig. 5, and coloring red 9. part I88 which will bevisible when the member is rotated sufficiently.

The operation of the above described device is as follows:

Assuming the vacuum cleaner to be assembled as shown in Fig. 1, rotationof the fan rotors II by the motor 2! causes them to draw air into thecasing through hose 10. If the cleaning tool attached to the other endof hose II is passed over a dusty surface, the dust will be picked upand carried by the air stream into the casing. The air passes throughdust separating member 44 which is supported by screen 43, while thedust is not permitted to pass through. The air discharged from the fanrotors passes through motor 25 as shown by the arrows, and is dischargedthrough outlet opening Il. Due to the sudden reduction in the velocityof the air stream when it enters the casing, a considerable proportionof the entrained dust will be precipitated and will settle in drawer 55.The remaining dust will adhere to the outer surface of the dustseparating member 44. When it is desired to remove the dust from thecleaner, the fan is stopped and the dust may be removed from member 44by pulling out and releasing handle 53, as has been previouslydescribed. This shakes the dust loose from the dust separating memberand this dust is collected in drawer 55. Thereafter knob 82 is turned soas to disengage threaded portion 83 from arm 58 and the drawer and itscontents may be withdrawn from the casing and emptied in any suitableplace.

The dust indicating member warns the operator when sufllcient dust hasaccumulated on the dust separating member to make it desirable to removethis dust. Dust separating member 44 offers a certain resistance to thepassage therethrough of air and hence the pressure in the space betweenthe inlet and the dust separating member is higher than the pressurebetween the dust separating member and the fan. As dust accumulates inthe dust separating member it increases the resistance to flow of airtherethrough and thus increases this difference in pressure. The higherpressure existihg between the inlet and the dust separating member iscommunicated to chamber in handle 53 by means of tube I6 and passage 19.This pressure is exerted against one side of diaphragm 85 and tends tomove the diaphragm so as to compress spring 88. The lower pressureexisting between the dust separating member and the fan is communicatedto chamber I4 in handle 53 through tube 46 and passage 13. In chamber 14this pressure is exerted against diaphragm 85. When, due to theaccumulation of dust on the dust separating member, this pressuredifference is great enough to overcome the force of spring 88, diaphragm85 and projection 91 will move to the right as viewed in Fig. 6, andthus permit spring 93 to rotate indicating member in clockwisedirection. This will cause the part Hill which. is painted red, ordistinguished in some other suitable manner, to appear below window 99.This will warn the operator that the dust should be removed from thedust separating member. This can be done by stopping the motor andshaking the dust separating member, as previously described.

It is not necessary always to empty the drawer after the dust separatingmember has been shaken. However, if, immediately after it has beenshaken and the motor is again started, the dust indicator again showsthat there is an excessive pressure drop through the dust separatingmember, this should be taken as a warning that the drawer should beemptied inasmuch as it contains so much dust that the air stream picksit up and deposits it on the dust separating member.

Figs. '7 and 8 show a somewhat modified embodiment of my invention. Thisembodiment differs from that illustrated in the previous figures in thatthe supporting member, here designated by reference character 43' isformed with an undulated surface, star-shaped in cross-section, in orderto provide a greater surface. The dust separating member 44 consequentlymay be made with a greater surface without occupying a greater overallspace. The greater the surface of the dust separating member, the lessresistance it offers to the passage of. air and hence the longer it maybe operated without requiring cleaning. The operation of this embodimentis otherwise similar to that previously described.

While I have shown two more or less specific embodiments of my inventionfor purposes of illustration, it is to be understood that the scopethereof is to be limited only by the appended claims viewed in the lightof the prior art.

What I claim is:

1. In a vacuum cleaner, a casing formed with an air inlet and an airoutlet and a drawer open- 4 ing, means for producing flow of air throughsaid casing, a dust separating member in said casing having a horizontalextent, a drawer removable through said opening and having imperviouswalls extending under said member for collecting dust separated from theair by said members, said drawer having a flange adapted to seal againstsaid casing, an arm secured within said casing and extending to withinthe space defined by said drawer, one wall of said drawer being cut awayto provide for passage past said arm, and means secured to another wallof said drawer for engaging said arm to secure said drawer in saidcasing with said flange in sealing relationship with said casing.

2. In a vacuum cleaner, a casing formed with an air inlet and an airoutlet, means for producing flow of air through said casing, a dustseparating member, and means for supporting said member within saidcasing and maintaining the entire surface of said member curved, theconvex side of said member facing said inlet with respect to thedirection of air flow, the area of said dust separating member beingsubstantially greater than the area of the supporting means, wherebysaid dust separating member is folded against said supporting means.

3. In a vacuum cleaner, a casing formed with an air inlet and an airoutlet, means for producing flow of air through said casing, asupporting member having an air pervious curved surface,

the convex side of said member facing said inlet with respect to thedirection of air flow, a dust separating member supported on the convexside of said member, the area of said dust separating member beingsubstantially greater than the area of said supporting member, wherebysaid dust separating member is folded against said supporting member,and a removable receptacle located beneath said members for collectingdust separated from the air by said dust separating member.

4. In a vacuum cleaner, a casing formed with an air inlet and an airoutlet, means for producing flow of air through said casing, asupporting member having an air pervious curved surface, the convex sideof said member facing said inlet with respect to the direction of airflow, a dust separating member supported on the convex side of saidmember, the area of said dust separating member being substantiallygreater than the area of said supporting member, whereby said dustseparating member is folded against said supporting member, an agitatormember slidablymounted in-said supporting member and in said casing andsecured to said dust separating member and movableto straighten out thefolds in said dust separating member, one end or said agitator memberextending outside said casing, and a removable receptacle locatedbeneath said dust separating member for collecting dust.

5. In a vacuum cleaner, a casing formed with an air inlet and an airoutlet, a motor fan unit within said casing for producing flow of airtherethrough, supporting means for said unit, a wire form having aconvex surface'facing said inlet secured to said'supporting member, adust separating member supported on the convex side of said form, thearea of said dust separating member being substantially greater than thearea of said wire form whereby said dust separating member is folded bythe air-flow against said wire form, and a removable-receptacle locatedbeneath said dust separating member for collecting dust.

6. .In a vacuum cleaner, acasing formed with an inlet opening-and anoutlet opening, means for producing flow of -air through said casing, adust separating member in the path of air flow, a movable hollow membersecured to said dust separating member and formed with an opening on oneside of said dust separating member, and differential pressureresponsive means carried by said hollow member and subjected to thepressure therein.

7. In a vacuum cleaner, a casing formed with an inlet opening and anoutlet opening. means for producing flow of air through said casing,--adust separating member in the path of air flow, a movable hollow membersecured to said dust separating member and formed with an opening on oneside of said dust separating member, a movable diaphragm carried by saidhollow member and subjected on one side to the pressure therein andmeans for communicating the pressure on the other side oi said dustseparating member to the other side of said diaphragm.

8. In a vacuum cleaner, a casing formed with an inlet opening and anoutlet opening, means for producing flow of air through said casing, adust separating member in the path of air flow, a movable hollow membersecured to and extending through said .dust" separating member andhaving an opening on one side thereof, a movable diaphragm carried bysaid hollow member and subjected on one side to the pressure msrem atube surrounding said hollow member and having an opening on the otherside of said dust separating member, and means connecting said tube withthe other side or said diaphragm 9. In a'vacuum cleaner, a casing formedwith an inlet opening and an outlet opening, a motor fan unit in saidcasing for producing flow of air therethrough, a dust separating memberbetween said inlet and thefan, a slidably mounted .tube extendingthrough said casing and being secured to "and extending through saiddust separating member, said tube'having an opening communicating withthe space between said dust separating member and said fan, a diaphragmcarried by said tube outside said casing and exposed on one side to thepressure within said tube, a second tube rigidly connected to the firstmentioned tube and extending through said casing and communicating withthespace between said-inlet and said=dust separating member, and meanscon necting said second tube with the other side of said diaphragm.

10. In a vacuum cleaner, a-casing formed with an inlet opening and'anoutlet opening, a motor fan unit in said casing for producing flow orair and extending through said casing and communicating with the spacebetween said inlet and said dust separating member, said handle member-formed with a passage connecting said second tube with the other sideof said diaphragm.

ll. In a vacuum cleaner, a casing formed with an inlet opening and anoutlet opening, a motor fan unit in said casing for producing flow oiair therethrough, a dust separating member between said inlet and thefan, agitating means for said dust separating member comprising twotubes. one within the other, extending through said casing, a hollowhandle member secured to the outer ends of said tubes, the longer ofsaid tubes extending through and being secured to said dust separatingmember and communicating with the space between said dust separatingmember and said fan, said agitating means being reciprocably.

mounted and resilient means tending to cause movement thereof in onedirection, and a diaphragm mounted in said hollow handle and exposed onone side to the pressure within-said longer tube, the shorter tubecommunicating with the space between said inlet and said dust separatingmember and with the other side of said diaphragm.

12. In a vacuum cleaner, a casing formed with an air inlet and an airoutlet, means for producing flow of air through said casing, asupporting member of rigid air pervious material,

said member being generally conical in shape and having an undulatedsurface to increase the area thereof, and a dust separating membersupported on said member, the area of said dust separating member beingsubstantially greater than the area of said undulated surface.

13. In 'a vacuum cleaner, an elongated noncirc'ular casing, a transversepartition disposed within-said casing and secured in air-tight relationto the interior thereof to provide separate compartments within saidcasing capable of sustaining different pressures, a motor-fan unitsupported "irom' said partition and arranged to produce asub-atmospheric pressure within one of said compartments, said partitionbeing formed with an aperture for flow of air produced by said motor-tanunit froms'aid one 01' said compartments, said partition serving tostrengthen said non-circular casing against atmospheric force actingonthe exterior of said one oi. said compartments, and a dust separatingmember disposed in said one of said compartments in the path or flow ofair therethrough.

14. In a vacuum cleaner, an elongated casing including a rounded uppershell and a substan- .,tially flat bottomed lower shell, said shellsbeing joined' together along a continuous air-tight longitudinal seam.said casing being formed with an inlet opening adjacent to one end andan outlet opening adjacent to the other end, said openings beingdisposed wholly on one side of said seam, transverse partition meanswithin said casing between said openings and secured in air-tightrelation to both said shells to provide separate compartments withinsaid casing capable of being subjected to different fluid pressures, amotorian unit supported from said partition means and arranged toproduce sub-atmospheric pressure within the compartment communicatingwith said inlet opening and to produce pressure higher than atmosphericin the compartment communicating with said outlet opening, saidpartition means serving to reenforce said casing against atmosphericpressure acting on the exterior of the first-mentioned compartment andagainst internal pressure acting on the secondmentioned compartment, anda dust separating member disposed in said first-mentioned compartmentsin the path of flow of air from said inlet opening to said motor-tanunit.

GUSTAF EINAR LOFGREN.

